This invention relates to improvements in photodichroic material information storage systems.
It has been known that crystals of photodichroic alkali halides, for example sodium fluoride, (NaF), can have color centers which can be manipulated by illumination with polarized ultraviolet light for the purpose of writing information therein, and can be read with polarized visible light for the purpose of reading information therefrom. However, the sensitivity of this storage arrangement, that is the ability to read what has been stored leaves much to be desired.